Hand labelling

On the other hand labeling studies have shown that the base promoted hydro lysis of chlorobenzene (second entry m Table 24 3) proceeds by the elimination-addition mechanism and involves benzyne as an intermediate... 

Semiautomatic Labeling. In this operation the machine selects, glues, and applies the label, but the item to which it is applied is placed into position by hand. Labels may be picked up by vacuum or the adhesive. The machine must be set up correctly, labels must be produced to certain critical limits, and the adhesive must be specially selected. A higher tack is necessary than that used for hand labeling. Speeds range from 25 to 60 per min (i.e., 3,600 per hr maximum). 

Requirements with respect to the label used to mark one of the immunoreagents are comparable to those in other postcolumn reaction detection systems [4]. The label should preferably allow sensitive and rapid detection and be nontoxic, stable, and commercially available. So far, mainly fluorescence labels have been employed (e.g., fluorescein), although, in principle, also liposomes, time-resolved fluorescence, and electrochemical or enzymatic labels are feasible. On the other hand, labels providing a slow response, including radioactive isotopes and glow-type chemiluminescence, are less suitable for immunodetection. 

The use of automatic labelling algorithms is normally justified in terms of saving time [384], [5], [279]. In the past, we had small databases which could be labelled by hand, but as the databases we use today are larger, and because sometimes we wish to label the database very quickly, we require an automatic system. This argument basically says that automatic labelling is therefore a matter of convenience if we had an infinite supply of hand labellers we wouldn t have a problem. A second justification is that automatic systems can out perform human labellers in terms of accuracy and consistency, and so convenience alone is not the only justification automatic systems are in fact better, in our experience this certainly appears to be true. 

It is inadvisable to measure the accuracy of an alignment system by comparing it to hand-labelled data, as the quality of hand-labelled data is usually worse than the best automatic systems. 

An issue that is seldom addressed on the issue of labelling is that of just what a labeller is doing when he or she hand labels some data. One sees the terms hand labelling and expert labeller quite frequently in this context, but what do these mean ... 

This realisation has led to the study of alternative HMM configurations built specifically for the purpose of ahgnment. Matousek et al. [23 5] report a number of experiments using tile HTK toolkit to label the data, whereby a small amount of hand-labelled data is used to provide initial models, which are then retrained on the full corpus. In Clark et al. 

There are two important types of labels in laboratories. The labels on commercial containers are usually extremely comprehensive, providing not only information on the nature, amount, and quality of the product but also a very laige amount of safety-related data. Typically a commercial label will readily meet the requirements of the hazard communication standard. On the other hand, labels placed on secondary containers in the laboratory by employees may be something such as soln. A or even less. This may be sufficient if all of the material is to be promptly used by the individual placing the label on the container, but otherwise it is not. In most instances, secondary containers of hazardous chemicals should be marked with labels identifying the chemical in the container and providing basic hazard warnings. The secondary label should be affixed before the container is put into use. 

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